Package com.tangosol.util.processor

Class ExtractorProcessor<K,​V,​T,​E>

  • All Implemented Interfaces:
    ExternalizableLite, PortableObject, InvocableMap.EntryProcessor<K,​V,​E>, Serializable
    public class ExtractorProcessor<K,​V,​T,​E>
extends AbstractProcessor<K,​V,​E>
implements ExternalizableLite, PortableObject
    ExtractorProcessor is an EntryProcessor implementations that extracts a value from an object cached in an InvocableMap. A common usage pattern is: 
       cache.invoke(oKey, new ExtractorProcessor(extractor));
    which is functionally equivalent to the following operation: 
       extractor.extract(cache.get(oKey));
    The major difference is that for clustered caches using the ExtractorProcessor could significantly reduce the amount of network traffic.

    An alternative (and superior) approach would be to use the ReducerAggregator

    Author:
    gg 2005.11.30
    See Also:
    Serialized Form

    • Field Detail

      • m_extractor

        protected ValueExtractor<? super T,​? extends E> m_extractor
        The underlying value extractor.

    • Constructor Detail

      • ExtractorProcessor

        public ExtractorProcessor()
        Default constructor (necessary for the ExternalizableLite interface).

      • ExtractorProcessor

        public ExtractorProcessor​(ValueExtractor<? super T,​? extends E> extractor)
        Construct an ExtractorProcessor based on the specified ValueExtractor.
        Parameters:
        extractor - a ValueExtractor object; passing null is equivalent to using the IdentityExtractor

      • ExtractorProcessor

        public ExtractorProcessor​(String sMethod)
        Construct an ExtractorProcessor for a given method name.
        Parameters:
        sMethod - a method name to make a ReflectionExtractor for; this parameter can also be a dot-delimited sequence of method names which would result in an ExtractorProcessor based on the ChainedExtractor that is based on an array of corresponding ReflectionExtractor objects

    • Method Detail

      • equals

        public boolean equals​(Object o)
        Compare the ExtractorProcessor with another object to determine equality.
        Overrides:
        equals in class Object
        Returns:
        true iff this ExtractorProcessor and the passed object are equivalent ExtractorProcessor objects

      • hashCode

        public int hashCode()
        Determine a hash value for the ExtractorProcessor object according to the general Object.hashCode() contract.
        Overrides:
        hashCode in class Object
        Returns:
        an integer hash value for this ExtractorProcessor object

      • toString

        public String toString()
        Return a human-readable description for this ExtractorProcessor.
        Overrides:
        toString in class Object
        Returns:
        a String description of the ExtractorProcessor

      • readExternal

        public void readExternal​(DataInput in)
                  throws IOException
        Restore the contents of this object by loading the object's state from the passed DataInput object.
        Specified by:
        readExternal in interface ExternalizableLite
        Parameters:
        in - the DataInput stream to read data from in order to restore the state of this object
        Throws:
        IOException - if an I/O exception occurs
        NotActiveException - if the object is not in its initial state, and therefore cannot be deserialized into

      • writeExternal

        public void writeExternal​(DataOutput out)
                   throws IOException
        Save the contents of this object by storing the object's state into the passed DataOutput object.
        Specified by:
        writeExternal in interface ExternalizableLite
        Parameters:
        out - the DataOutput stream to write the state of this object to
        Throws:
        IOException - if an I/O exception occurs

      • readExternal

        public void readExternal​(PofReader in)
                  throws IOException
        Restore the contents of a user type instance by reading its state using the specified PofReader object.
        Specified by:
        readExternal in interface PortableObject
        Parameters:
        in - the PofReader from which to read the object's state
        Throws:
        IOException - if an I/O error occurs

      • writeExternal

        public void writeExternal​(PofWriter out)
                   throws IOException
        Save the contents of a POF user type instance by writing its state using the specified PofWriter object.
        Specified by:
        writeExternal in interface PortableObject
        Parameters:
        out - the PofWriter to which to write the object's state
        Throws:
        IOException - if an I/O error occurs